The Holocaust Educational Trust said Mr Livingstone was “promoting a misleading and misinformed version of history to further his agenda”.

He faces a charge of engaging in conduct that was grossly detrimental to the party.

During an interval in Friday’s session, Mr Livingstone said the case against him was “weak” and suggested many of the allegations, including that he was an anti-Semite, had since been “retracted”.

“For the first time I’m beginning to think I might actually not be expelled,” he said.

The row erupted in April 2016, when he was defending Labour MP Naz Shah over accusations she had made anti-Semitic social media posts.

He told BBC London: “When Hitler won his election in 1932, his policy then was that Jews should be moved to Israel. He was supporting Zionism before he went mad and ended up killing six million Jews.”

This sparked criticism from historians, Jewish groups and Labour colleagues and he was later confronted outside the BBC’s studios by Labour MP John Mann, who accused him in front of TV cameras of being a “Nazi apologist”.

Mr Livingstone was suspended from Labour by party leader Jeremy Corbyn.

Following Friday’s hearing, Mr Livingstone said it was nonsense to suggest he ever said Hitler was a Zionist.

“They now accept I didn’t say it,” he said.

“The only issue is, was it right to defend Naz Shah? And I was simply saying Naz Shah isn’t anti-Semitic.

“If she was anti-Semitic, they wouldn’t have readmitted her to the Labour Party.”

He said the hearing was “an amazing debate about the meaning of words. I feel now I could qualify for a degree”.

Anti-Semitism and Zionism

Anti-Semitism is “hostility and prejudice directed against Jewish people” (OED)

Zionism refers to the movement to create a Jewish state in the Middle East, corresponding to the historic land of Israel – anti-Zionism opposes that

Some say “Zionist” can be used as a coded attack on Jews, while others say the Israeli government and its supporters are deliberately confusing anti-Zionism with anti-Semitism to avoid criticism

In a written submission to his disciplinary hearing, Mr Livingstone accused Labour of pursuing the case against him in a “partisan” way and suggested there was a witch hunt aimed at critics of Israel.

Arriving on the first day of the two-day hearing, he repeated his comment that Hitler had supported Zionism, adding that the Nazi paramilitary SS had set up training camps for German Jews so they “could be trained to cope with the very different sort of country when they got there”.

Mr Livingston’s original comment was described as inaccurate by Yale University history professor Timothy Snyder in a BBC article in April.

And speaking on the BBC’s Daily Politics, Mike Katz, the national vice-chairman of Jewish Labour, said he was repeatedly asked on the doorstep when canvassing in Jewish areas “has Ken been expelled yet?”

But Jonathan Rosenhead, of Free Speech on Israel, said that to say you could not talk about Israel in the same context as Nazism “is to restrict political discussion – we need free speech”.